The present invention relates to a lifting or handling appliance and, more particularly, to a crane which has multiple configurations and functions, especially with regard to its jib.
In the crane sector, power cranes are particularly known, the preferred use of which is the construction of buildings of parallelepipedic general shape.
The state of the art includes, in particular, power cranes with a foldable or telescopic mast, having a system for retaining the jib. A typical example of these is given in French Patent No. 91 12384/2 682 096 filed on Feb. 10, 1991 in the Applicant""s name. For such cranes, it is known to produce foldable jibs in the form of a plurality of successive elements, inter alia jibs with an intermediate folding sectionxe2x80x94see, for example, French Patent No. 91 12383/2 682 097 filed on Feb. 10, 1991 in the Applicant""s name.
In order to put such a crane into operation at a given location, the configuration of the crane must be predetermined before mounting or the crane must be demounted in order to change its configuration, a choice having to be made, in particular, between the following configurations:
crane with horizontal distribution jib,
crane with xe2x80x9cswanneckxe2x80x9d distributor jib,
crane with inclined distributor jib, forming, for example, an angle of 30xc2x0 to 45xc2x0 relative to the vertical,
raisable flying jib crane.
The working bulk of the crane is determined by the selected configuration and does not make it possible to elude aerial obstacles, such as preexisting buildings, electrical lines, bridges, other nearby cranes, etc.
The bulk of the crane during the mounting of the latter is determined, in respect of a selected configuration, by the kinematics of the crane and cannot be modified.
The inoperative bulk of the crane, especially when the crane is put into the xe2x80x9cslewingxe2x80x9d mode, may also be large and cumbersome.
The present invention aims to avoid all these disadvantages by providing an appliance of novel design, which adapts easily and quickly to the conditions of even overcrowded work sites, by virtue of a modifiable configuration which, furthermore, allows a multiplicity of uses of the same appliance.
For this purpose, the subject of the invention is essentially a crane with jib having multiple functions, the crane comprising a mast, mounted on a chassis, and a distributor jib composed of at least two successive elements articulated on one another about horizontal axes, the first jib element being articulated by means of its rear part about a horizontal axis on the top of the mast, and all the jib elements comprising a rolling track for a carriage, this crane being defined in that a least the first jib element is capable of being brought into a substantially vertical position in alignment with the erected mast, so as to increase the height of said mast.
According to a preferred embodiment of the invention, the distributor jib of the crane is composed of three successive jib elements, namely a jib foot, an intermediate jib element and a jib tip, which are articulated on one another about horizontal axes, and the crane is intended to be capable of being used with only the jib foot brought into a substantially vertical position in alignment with the erected mast or else of being used with the jib foot and the intermediate jib element both brought into a substantially vertical position in alignment with the erected mast.
Advantageously, the mast of the crane comprises, at its top, a bearing face which is substantially horizontal and faces upward when the mast is erected and which is intended to cooperate with a complementary bearing face located at the rear of the first jib element or jib foot. The cooperation of these two bearing faces ensures that forces are transmitted when the first jib element is aligned with the erected mast.
The invention is thus defined mainly in that at least one element of the jib, preferably two jib elements, can be temporarily aligned with the mast and thus form part of this mast of which they constitute a xe2x80x9clengtheningxe2x80x9d piece, the other element or elements then forming a more or less shortened useful jib.
Moreover, the element or elements of the jib which are not used as mast parts may be used selectively in various configurations by virtue of the multiple joints provided, especially so as to form a horizontal distributor jib, an inclined distributor jib, a xe2x80x9cswanneckxe2x80x9d jib or a raisable jib. Where this last use is concerned, it is advantageous if the jib possesses at least one element which pivots about a horizontal axis located at the top of the mast or at the upper end of a jib element aligned with the erected mast, whilst the jib tip is kept in a substantially horizontal position and maintains a distributor function. The raisable jib may also be of the distributor type over its entire length and over a wide deflection angle, all the elements of this jib (which are not used as a mast part) remaining aligned.
By virtue of its particular features, the crane which is the subject of the invention makes it possible to adapt the characteristic load/range curves, more particularly for the construction of buildings of parallelepipedic shape. Moreover, the invention makes it possible to adapt the configurations of the crane to overcrowded work sites, in order to make use of normally prohibited zones and have access to zones where access is impossible for traditional lifting or handling appliances (mobile cranes, carriages with a telescopic raisable arm, site cranes). It will be noted that the working configurations of the crane which is the subject of the invention are all the more numerous and varies because the abovementioned configurations of the jib elements may be combined with variable configurations of the mast, especially if the mast is foldable or telescopic and can thus be used in several positions.
Furthermore, by virtue of its structure and its multiple positions of use, the jib of the crane which is the subject of the invention may advantageously receive, at its front end, a piece of equipment, accessory or apparatus, for example of jib lengthening piece, a pod or a fork, carried by a support which, in turn, is mounted pivotably about a horizontal axis at this end of the jib, thus further multiplying the possibilities of use of the crane.
It will also be noted that the various joints of the crane, especially those of the jib, are advantageously motorized by means of devices with jack or with jack and linkage, making it possible to change from one configuration to another easily and quickly, for example in order to bring a jib element into alignment with the mast or, conversely, in order to return this element with a position in which it belongs to the useful part of the jib.